This device relates to a safety belt. The general operation of a safety belt is known. The safety belt is mechanically coupled to a buckle (“buckled”) around a user, which partially restrains the user. When the user moves forward, the buckle engages and prohibits further forward motion. Several theories of how to build such a device exist as will be described below.
U.S. Pat. No. 7,862,087 (Martinovic) teaches a hydraulic cushion for a safety belt, however Martinovic accomplishes this with a tooth and bore variety of orifice device as oppose to disclosed invention, which uses a specially shaped orifice plate. U.S. Pat. No. 7,828,331 (Jessup) also teaches a hydraulic cushion for a safety belt, similar to the disclosed invention Jessup uses a rotary formation with a rotor blade (which Jessup calls a wiper blade). Unlike the disclosed invention Jessup uses a throttle valve and a series of fluid chambers. Jessup and Martinovic both teach away from a specially shaped orifice plate that can guide the flow of hydraulic fluid. U.S. Pat. No. 6,209,916 (Smithson) combines the multiple chambers of Jessup and the tooth and bore system of Martinovic to create a “restriction flow path.” Martinovic emphasizes how prior teaching cannot result in the disclosed invention. The prior art, alone or in combination teaches a “restriction flow path” and not a specially shaped orifice plate. Additionally, Martinovic, Jessup and Smithson are limited in their effectiveness by the shape of internal components in their devices. In particular, the orifice plate described below is unique to these references and the rest of the prior art.